It represents the item interactability in <img src="/ubbthreads/images/graemlins/div.gif" alt="" />.
Personaly i believe Alchemy can and should be more complex..its not enough you mix mushrooms to make a potion.
A health potion should be able to combine alot of ingreidents. After Investing in the skill, you should then be able to use the alchemists set with the various ingridents e.g a health potion consists of a red mushroom/bread/a special herb/water and other things.
After mixing them together you make enough for 5 small flasks.
As you invest more in the skill your healing potions become better but require more time to make as well as being more complicated.
So for medium health potions you may need to add more ingridents or may to need to heat it. Large healing potion may require you to let it stand for 1 day or so before it is ready to use and reqire a large cauldron or so for you to buy/aquire.
There is a chance of failure of course which decreases the more you invest in the ability.